South African intelligence secretly backed loyalist paramilitaries during the 1970s, according to a new book on the Kincora sex scandal.

Award-winning journalist Chris Moore claims William McGrath, house master at the notorious east Belfast hostel, fostered links between shadowy loyalist group Tara and ultra right-wing groups in southern Africa.

In The Kincora Scandal, published this Thursday, Moore says McGrath, an MI5 agent who was eventually jailed in 1981 for abusing boys in care, sent operatives to South Africa and Rhodesia.

One Tara member, Charles Simpson, was dispatched to Salisbury in 1976 to train with the Rhodesian army. He returned briefly to Ulster in the late 1970s before settling in South Africa. In July 1985, Brian Nelson, a senior UDA intelligence officer, arrived in Durban to arrange a huge arms shipment bound for Ulster.